Data domain
hideIn data management and database analysis, a data domain refers to all the unique values which a data element may contain. The rule for determining the domain boundary may be as simple as a data type with enumerated list of values.
For example, a database table that has information about people, with one record per person, might have a "gender" column. This gender column might be declared as a string data type, and allowed to have one of two known code values: "M" for male, "F" for female -- and NULL for records where gender is unknown or not applicable (or arguably "U" for unknown as a sentinel value). The data domain for the gender column is : "M", "F".
In a normalized data model, the reference domain is typically specified in a reference table. Following the previous example, a Gender reference table would have exactly two records, one per allowed value -- excluding NULL. Reference tables are formally related to other tables in a database by the use of foreign keys.
Less simple domain boundary rules, if database-enforced, may be implemented through a check constraint or, in more complex cases, in a database trigger. For example, a column requiring positive numeric values may have a check constraint declaring the values must be greater than zero.
This definition combines the concepts of domain as an area over which control is exercised and the mathematical idea of a set of values of an independent variable for which a function is defined. See: domain (mathematics).
For more information about Data domain, read the full article at
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News tagged with data domain
EMC raises offer for Data Domain
Jul 06, 2009 |
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Computer storage giant EMC raised its offer to purchase data storage firm Data Domain on Monday in a bid to top a rival offer for the company by data management firm NetApp.
NetApp claims victory in bidding for Data Domain
Jun 04, 2009 |
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(AP) -- NetApp Inc. has claimed victory over EMC Corp. in a bidding battle for Data Domain Inc., a company whose products help cut unnecessary data storage.
EMC counters NetApp bid for Data Domain
Jun 01, 2009 |
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US computer storage giant EMC Corp. offered 1.8 billion dollars on Monday for Data Domain in a bid to counter a rival offer for the data storage company from NetApp.
NetApp to buy Data Domain in $1.5 billion deal
May 21, 2009 |
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(AP) -- Data storage company NetApp Inc. said Wednesday it agreed to buy data backup and disaster recovery systems provider Data Domain Inc. for $25 per share in cash and stock, or about $1.5 billion.
Search results for data domain
New research into the mechanisms of gene regulation
Nov 19, 2009 |
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(PhysOrg.com) -- A team led by Penn State's Ross Hardison, T. Ming Chu Professor of Biochemistry and Molecular Biology, has taken a large step toward unraveling how regulatory proteins control the production ...
Reference Genome of Maize Published (w/ Podcast)
Nov 19, 2009 |
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(PhysOrg.com) -- A four-year, multi-institutional effort co-led by three Cold Spring Harbor Laboratory scientists culminated today in publication of a landmark series of papers in the journal Science reveal ...
Scientists put interactive flu tracking at public's fingertips
Nov 16, 2009 |
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New methods of studying avian influenza strains and visually mapping their movement around the world will help scientists more quickly learn the behavior of the pandemic H1N1 flu virus, Ohio State University ...
Viagra for women? Drug developed as antidepressant effective in treating low libido
Medicine & Health / Medications
Nov 16, 2009 |
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The drug flibanserin, which was originally created as an antidepressant, is effective in treating women with low libido, pooled results from three separate clinical trials have found.
Professor uses video games to explore facets of autism
Oct 13, 2009 |
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(PhysOrg.com) -- Matthew Belmonte, assistant professor of human development, is looking for order behind the many behavioral and physiological features of autism.
Declines in other thinking and learning skills may precede memory loss in Alzheimer's disease
Medicine & Health / Neuroscience
Oct 12, 2009 |
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Cognitive abilities other than memory, including visuospatial skills needed to perceive relationships between objects, may decline years prior to a clinical diagnosis in patients with Alzheimer's disease, according to a report ...
French arrest physicist suspected of al-Qaida link
Oct 09, 2009 |
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(AP) -- A nuclear physicist working at the world's largest atom smasher has been arrested on suspicion of links to the Algerian branch of al-Qaida, another blow to a project that has been plagued by glitches and was shut ...
New method reveals all you need to know about 'waveforms'
Oct 07, 2009 |
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The National Institute of Standards and Technology has unveiled a method for calibrating entire waveforms -- graphical shapes showing how electrical signals vary over time -- rather than just parts of waveforms as is current ...
Banking on outlier detection: Simple computer model could act as early warning system for failing banks
Oct 07, 2009 |
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Recent bank failures point to the continuing need for vigilance by regulators and investors. Now, a report in the International Journal of Operational Research, discusses the possibility of an early-warning system that s ...
Filming photons, one million times a second
Oct 05, 2009 |
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(PhysOrg.com) -- European researchers have created a CMOS (semiconductor) camera capable of filming individual photons one million times a second. The breakthrough will impact on all the most advanced areas ...
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